package thinkinjava.c15_generics.coffee;

import net.mindview.util.Generator;

import java.lang.reflect.InvocationTargetException;
import java.util.Iterator;
import java.util.Random;

/**
 * @Auther DRevelation
 * @Date 2020-05-11 上午 10:40
 * @Desc Generator使用
 */
public class CoffeeGenerator implements Generator<Coffee>, Iterable<Coffee> {

    private Class[] types = {
            Latte.class, Mocha.class, Cappuccino.class, Americano.class, Breve.class
    };
    private static Random rand = new Random(47);

    private int size = 0;
    public CoffeeGenerator() {}
    public CoffeeGenerator(int size) {
        this.size = size;
    }

    @Override
    public Coffee next() {
        try {
            return (Coffee) types[rand.nextInt(types.length)].getDeclaredConstructor().newInstance();
        } catch (IllegalAccessException | InstantiationException | NoSuchMethodException | InvocationTargetException e) {
            e.printStackTrace();
            throw new RuntimeException(e);
        }
    }

    @Override
    public Iterator<Coffee> iterator() {
        return new CoffeeIterator();
    }

    class CoffeeIterator implements Iterator<Coffee> {
        int count = size;

        @Override
        public boolean hasNext() {
            return count > 0;
        }

        @Override
        public Coffee next() {
            count--;
            return CoffeeGenerator.this.next();
        }

        @Override
        public void remove() {
            throw new UnsupportedOperationException();
        }

        public Iterator<Coffee> iterator() {
            System.out.println("===可调用了===");
            return new CoffeeIterator();
        }
    }

    public static void main(String[] args) {
        CoffeeGenerator gen = new CoffeeGenerator();
        for (int i = 0; i < 5; i++) {
            System.out.println(gen.next());
        }

        for (Coffee c : new CoffeeGenerator(5)) {
            System.out.println(c);
        }
    }
}
